This invention relates to a curtain wall system for cladding of buildings and in particular to methods of joining metal members used for construction of window frames or other panels for such cladding.
In or U.S. Pat. No. 4,631,884 there is described a novel wall system which comprises an auxiliary framework attached to the main steel work of a building and made of a plurality of framework members. Each such framework members has a generally T shaped cross section and includes an elongated central support portion defining a pair of opposed shoulders for seating the edges of a pair of adjacent infill panels. The framework member has a channel generally parallel with the support portion and shaped to receive and grip the foot of a flexible gasket, the gasket having a transverse limb adapted to extend toward or over the associated shoulder to bear against the infill. The thickness of any given infill may be substantially the same as the cross sectional length of the support portion of the associated framework member. The term "curtain wall" as used herein is intended to cover systems of this type as well as conventional curtain wall systems.
One advantage of the system above described is the flexibility accorded the system to enable subsequent alterations and/or extensions to be accommodated. Thus the removal of one gasket allows its associated infill to be removed and replaced with, for example, an infill bearing an opening window, without disturbing adjacent infills or rention devices. (The term infill includes a construction panel, glazing unit, or the like which is capable of being used as cladding for a building, that is to constitute the internal and external walling for a building.)
Construction of curtain walling from extruded metal members has previously involved use of brackets or jointing blocks which are secured to the abutting members by screws or bolts. Such arrangements have the disadvantage that diurnal thermal movements create noise and cause annoyance to occupants of the building.